Pit furnace



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G. KEHREN PIT FURNACE Filed June 23, 1927 l 1537.1.

Patented Jan. s, 1929.

UNITED STATES GOTTFBIED HEEREN, l' DUSSELDORF, GERMANY.

PIT FUB'NACE.

Application illed June 23,A )1927, Serial No. 200,012, and in' Germany June 30, 1926,

This invention relates to it furnaces and f has for its object to .provi e an improved construction for furnaces of this character. For this urpose it is known to employ n coal dust firing for the usual push and roll or continuous furnaces, wherein said ingots` are moved forward from behind by mechanical devices or are rolled forward by hand. The rolling of large cast in ots has 'lu proved however to be attended y considerable diiculties and for this reason it has become customary to heat the ingots standing upright in pit furnaces. In these furnaces the use of coal dust firing was ls found to be diflicult in that it was not poss`ible to obtainl full development of the flame.

This invention obviates these difficulties and provides a it furnace with coalvdust firing wherein 4eating of the ingots is achieved with satisfactory utilization of the lheat contents 'of the flame. According to" the invention at least one combustion chamber is arranged laterali beside the heating hearth, the lateral wal opposite to the said hearth heating by direct radiation` Y in ots situated on said hearth. l

hei-invention is illustrated by way of example in the accompanying drawings in which:` Fig. l is aside elevation of the new pit furnace, partially in section. n

Fi 2 a plan view thereof, the cover closm t e same being shown removed fonthe sage of clearness, and

Fig. 2.

The heatin furnace accor ing to the invention is. effectedl bottom of which the ingots rest; The said ingots are brought in a comparatively cool condition by a crane A to that-gfendcf the chamber D at which is 'situatedfthe dis-l charge conduit C for the heating gases (to the left 'hand in the drawings) and, when they have been sufficiently preheated at the point of entry are moved by the crane Aj gradually furt er and further towards the end where the combustion gases are introduced `(to the right in Figs. .1 and 2) thatv is, in the direction of the soca1led re-heating hearth'D; thence they are removed in a highly heated white-hot condition and treated in known manner.

The top o f the chamber D is closed by Fig. a is a section on. the 1min-HI in in a longitudinal furnace chamber D on thai anr arched cover E which v can travel` fr on i the same from over the furnace or to push j it back thereover. By coupling one or more of dthe other travelling carriages E with the last carriage by means of' the cou ling devices G anv desired number o arched covers may e moved aside simultaneously so. that the hearth can be uncovered at any desired point for the purpose of introducing or removing the ingots- B.

K is a combustion chamber disposed'at v oneside of the hearth D at the end of the furnace opposite to that of the outlet C, is a second such combustion chamber which' is arranged on the other side *symmetrically to the longitudinal axis of the furnace.` It is clear that the furnace might also be furnished merely with one combustion chamber arranged on one side. .The combustion chambers are comparativel narrow' and extend inthe longitudinal d1- rection of the furnaceand of the hearth D'. Nozzles L, L to which conduits'l, l are'connected are provided in those end walls 1c, lc of the chambers K, K which areA towards the centre of the furnace." Co'al dust is introduced into these conduits from a container M with the assistance 'of lcoml .A `pnessed air supplied by a blower N by well of the ingotsB in the pit x lcombustionv gases flow from the chambersV K, K through the chamber D (in the drawv ing from the right to left) and ass through the outlets C into the stack. he radiant heat of the flame between the end walls 7c, k and the radiant heat of thel highly directly upon the ingots 'situated at the right hand end of. the chamber D and already stron ly pre-heated;l said ingots are thus broug t to the desired .temperature and the heatmg gases passing on tothe outlet preheat the ingots to be treated which are moved 106v heated lateral walls of the chambers acts Theexpression reheatin hearth as em- ,Ployd rintheprese'n tspeci cation as well as in thel claimsywllbe lunderstood to refer" more .especiall'yftotliat portion of the heating hearth upon; which the blanks to be peratures s 'reduced4 *within -the lieatin chamber.

Q Y the reheatng hearthware'thus exposed `to :arranged combustion.' chambers an :ff becomea intensely. and uniformly heated in .combustion `chambers toward said closed Y transverse end wall, the, inwardly-presented e blanlisv which have 'reach theiiniowingburning-gases from optpositely preparation, forH example,.of the*V rolling #process"whitihnfolloma4 fIfit appears' to be neceaiicompressed.

besu plied b Way o `a conduit -P O of t e; furnace opposite to inthe endw that lof the outlet-C andinay be introduced for mixture withl the 4combustionl gases by 'meansof outlet-passages`p.l

described my 1'.' .In a it elo ted eating chamber provided with a disc ar e outlet\at one end and a closed said heating chamber, a fuel [inlet arranged in `the" end wall of said lcombustion chamber -farthest' from said, closed end wall and dischargingalong the inner lateral wall of said combustion-chamber towardsaid closed end wall ofthe :heating chamber,

-, l the inwardly-presented lateral wall of saidv combustion v chamber and the closed transverse end wall. f Asaid heating chamber being adapted and arranged to radiate heat to ingots 'dispo t ,l means for moving said in'gots `from the outsed y' adjacent thereto 'and opening laterally linto sai ja closed transverse wall extending across f' said heatin .chamber and said `combustion h chambers, el'inlets arranged in the inner u ence furnace, the 'combination-of ali' let end of said heating `chamber 4towardthe i closed end thereofandjinto positionV adjacent to said combustion chamber..` t

2. In aV pit furnace, the combination of an elongated heatin chamber provided at one end with a disc arge outlet and at its I opposite vend* with elongated 'combustion "heated are subjected tothe highest temambers' arrangedyon opiosite sides of and l end walls of said combustion' chambers and heating chamber,

discharging over the inner side walls of saidV lateral walls of said combustion lchambers tuting-vheat-radiating walls fori ingots ar-` ranged adjacent thereto, and means for movingl said in ots from `the discharge outr "ilet vend of said invention,

eating chamber 'toward the 4closedV end thereof.A

3. In a pit furnace, the combination with heating chamber provided at one end withV .1an outlet conduit, of combustion chambers i arranged on opposite sides of said' heating "chamber at the other end thereof and opening tliereinto through the side walls of fsaid `heating chamberfa fuel-conduit dis-v charging. into each ofsaid combustion chambers in a direction away from -said outlet conduit, a'closed transverse wall ex- -tending across said combustion chambersV chamber at ,the endfar` and the heatin thest' `from sai outlet conduit, and a'con duit for compressed air discharging through said closed transverse wall. into said-combustion chambers and heating chamber.v

In testimony. whereof I have aixed my signature. v

eio'i'irizinn` KEHRE'N'.'

yand-said Yclosed transverse end wall consti# 

